The invention is concerned with a channel device, especially for recordings of thermal conductivity, viscosity, density, dielectric constants, refractive indices, etc. of materials such as fluids and gases (called samples), where the material under investigation is guided through a measuring channel with at least one sensor and at least one inlet and one outlet orifice for the sample. The invention also concerns the fabrication procedure of the channel device, especially the recording unit for determining the thermal conductivity, viscosity, density, dielectric constant, etc. of samples where the material under investigation is passed through or brought into a measuring channel which is equipped with sensors and actuators.
The aim of the invention is to create a measuring arrangement capable of on-line recordings which is extremely sensative even for a very small sample volume and can be miniaturized for mass production, using photolithographic, thin-film and solid-state techniques. The invention is characterized by a channel, formed by a substrate (or carrier) and a layer, forming a wall, which is arranged a certain distance from the substrate. The layer is deposited by evaporation, spin-on, sputter, drop-on, reactive deposition, CVD, PECVD, etc., techniques and consists ie. of synthetic material, glass, ceramic, Si3N4, SiO2, SiO, combinations of these materials, etc. The invention is also characterized by the fact that the sensors and actuators are formed by layers on and/or in the substrate and /or in the wall forming layer, ie. by evaporation, spin-on, sputter, drop-on, reactive deposition, CVD (chemical vapor deposition), PECVD (plasma enhanced chemical vapor deposition), etc. techniques.
The process invention is characterized as follows: a dissolvable substance is deposited on the substrate, forming the inside of the channel, consisting of ie. photoresist, synthetic material etc. The dissolvable substance is covered afterwards by the wall forming layer, which also covers at least parts of the substrate where the substrate is free of dissolvable substance. The layer adheres well on the substrate and forms, together with the substrate, the measuring channel. The dissolvable substance can be dissolved and removed through the inlet and outlet orifices using solvents and solutions which are not dissolving or attacking the wall forming layer or the substrate.